Late September can bring some of the best early evening experiences for those who enjoy looking upwards.

Visibility is likely to fluctuate a bit, but it looks as though we may get some of the best stargazing weather of the year over the next few nights. It promises to be warm enough to enjoy long spells outside, but without the crazily late sunsets of midsummer.

I’ll point out a few of the things worth looking for in a minute, but first just a few words about this weather.

On my courses I encourage people to take note of shifts in wind direction and how this relates to changes in weather patterns. If the weather is unseasonably warm or cold, we should expect some deviation from the prevailing wind direction, southwest.

The image above shows the UK (at lunchtime tomorrow) sandwiched neatly between a high pressure system over the continent and a couple out in the Atlantic. Winds rotate clockwise around a high pressure system and anti-clockwise round a low pressure. The net effect for us will be winds that will be coming from the south and southeast. Southerly winds tend to bring warmer air, and southeasterly winds from over the continent bring drier air than the moist southwesterly winds from over the Atlantic. Hence the warm and dry conditions.

On to the night sky…

As the sun sets the brightest stars will start to show their face. The bright yellow and orange Arcturus will appear low in the west not long after sunset.

In the south there will be three bright white stars worth looking for. Search for a large triangle that occupies the high southern sky. This triangle is made up of the three brightest stars, Altair, Deneb and Vega, from the constellations Aquila, Cygnus and Lyra. It is not surprising that sailors have learned to abbreviate this family to the nickname ‘The Summer Triangle’ or ‘The Navigator’s Triangle’.

The star of the show will undoubtedly be Jupiter, rising at about 8pm just north of east, he will be ruling the eastern sky with pomp by 9.30pm.

Many, many people will accuse this majestically bright white object of being Venus, Sirius or the North Star.

In reverse order, it can’t be the North Star as that is not a particularly bright star (and, as you may well have deduced, is in the north not the east) and it couldn’t be Sirius as Orion is nowhere to be seen. There is no way that it could be Venus, as Venus lives near the sun. If the sun has set then it is well to the west of us and we are looking east.

If you are up early in the mornings, Orion will be on watch over the southern sky, with Sirius burning brightly not far below him.

Enjoy.

My thanks to Mark Evans who not only flew over from Oman for a course, but also sent me this great time lapse photo from Oman.

Mark is the General Manager of Outward Bound Oman, which does not sound like the worst job in the world to me! Outward Bound Oman, under Mark’s leadership, is teaching young Omanis many outdoor skills, including traditional methods of desert navigation.

Time for a bit of fun. Which way are we looking in this picture and why?

Answers by email please. I’ll post the correct answer in a couple of days.

Update.12/05/11.

We are looking just south of west. approx 255 degrees. Orion’s belt can be seen setting about one third the way in from the right. The arcing to the right is anticlockwise around the North Celestial Pole, to the left the stars are arcing clockwise around the South Celestial Pole. The few stars that appear to be moving in a straight line are marking the celestial equator and where they cross the horizon (the imaginary sea level one) will be due west.

One way we can tell it is west, not east, is because of the shape of Orion: the bright orange Betelgeuse (Beetlejuice) of the hunter’s top left shoulder is above his belt. Other stars visible include the brightest of the lot, Sirius (half way in and low), Procyon (half way in and high), Castor and Pollux (top right, behind tent cord) among others.

Well done to those who got it. Better luck to those who were only out by 180 degrees, bizarre though it sounds you were closer to the right answer than if you had said north or south.

This morning I enjoyed a view of Orion, Sirius, Leo, which has just marched ahead of the dawn sun now, and a few other players. I took this photo of Orion’s Sword hanging down to the left (eastern) side of a large beech tree and dangling down towards the south, as it does. The ‘smudge’ in the middle is the Great Nebula in Orion, also known less romantically as ‘M42′. It is a ‘stellar nursery’ where new stars are born. Would a more appropriate term not be a ‘stellar maternity ward’?

On a different subject, my best wishes and good luck to Kevin Shannon who is attempting a zero-emissions circumnavigation of the globe. He asked me for my thoughts, and here they are (co-posted on his blog too):

“Emerging Expeditions

I met Kevin at the Outdoors Show in Birmingham in March and remember our encounter well, which, considering that I met at least two thousand people in three days, must say something about Kevin and his unusual project. I am lucky in that my work allows me to cross paths with a wonderfully varied crowd. Some of the paths are on the ridges of windswept mountains and others run through the Birmingham NEC, but even with the variety that comes from walking through wildernesses and urban jungles, there was something about Kevin’s expedition that resonated, something that kept it in my mind.

Modern expeditions tend to strive for a ‘noteworthy audaciousness’: the fastest, the youngest, the first all-female team to reach… This is often driven by a need for sponsorship, but also, if we are honest it is because nobody likes to risk their life, or livelihood or even just their time and effort for something that may go entirely unnoticed. We all like to leave a mark of some sort. From the boldest adventurers to timid individuals, everyone lives in fear of their short time on this planet going completely unnoticed. Increasing numbers are choosing to battle this fear by throwing fear at it and there is vast range in the methods people are choosing. From racing to the North Pole to queuing at X-Factor auditions.

What I like about Kevin’s expedition is that its noteworthiness comes from stripping something away. In his case emissions have been stripped away, but I think this may prove to be part of a significant trend and I am not referring to the climate here. The expeditions of the future may strive for noteworthiness by embracing minimalism, not by adding bells and whistles. In time I think the minimalism may come to include the scale of the expedition itself, but it is not quite time for that yet. This is something that a man who has set out to circumnavigate the globe will be most aware of.

Good Luck Kevin!”

Orion and his sword were first to offer their greetings and then I noticed Jupiter still visible in the southwest. Sirius, Betelgeuse, Capella, the Plough and Polaris sketched out some order in the celestial sphere.

The moon was close to setting and was lighting up rows of fluffy cumulus clouds on their western edges. As time passed the clouds lost their bright white western edges, but gained pink and orange eastern ones. They moved sedately towards the northeast, signalling the start to a fine day. (Photo to the right was taken a few minutes ago.)

“He stood and carefully examined the sky, to ascertain the time of night from the altitudes of the stars. The Dog-star and Alderbaran, pointing to the restless Pleiades, were halfway up the Southern sky ,and between them hung Orion, which gorgeous constellation never burnt more vividly than now, as it soared forth above the rim of the landscape. Castor and Pollux with their quiet shine were almost on the meridian: the barren gloomy square of Pegasus was creeping round to the north-west; far away through the plantation Vega sparkled like a lamp suspended amid the leafless trees, and Cassiopeia’s chair stood daintily poised on the uppermost boughs. ‘One o’clock,’ said Gabriel.”

…

“The sky was clear – remarkably clear – and the twinkling of all the stars seemed to be but throbs of one body, timed by a common pulse. The North Star was directly in the wind’s eye, and since evening the Bear had swung round it outwardly to the east, till he was now at a right angle with the meridian. A difference of colour in the stars – oftener read of than seen in England – was really perceptible here. The sovereign brilliancy of Sirius pierced the eye with steely glitter, the star called Capella was yellow, Alderbaran and Betelgeux shone with a fiery red.
To persons standing alone on a hill during a clear midnight such as this, the roll of the world eastward is almost a palpable movement. The sensation may be caused by the panoramic glide of the stars past earthly objects, which is perceptible in a few minutes of stillness, or by the better outlook upon space that a hill affords, or by the wind, or by the solitude; but whatever be its origin, the impression of riding along is vivid and abiding. The poetry of motion is a phrase much in use, and to enjoy the epic form of that gratification it is necessary to stand on a hill at a small hour of the night, and, having first expanded with a sense of difference from the mass of civilized mankind, who are dreamwrapt and disregardful of all such proceedings at this time, long and quietly watch your stately progress through the stars. After such a nocturnal reconnoiter it is hard to get back to earth, and to believe that the consciousness of such majestic speeding is derived from a tiny human frame.”

I will try not to spoil the moment by pointing out that if Castor and Pollux were ‘almost on the meridian’ then it would be hard to see the square of Pegasus in the way that Hardy describes. I will try but fail. Rare is the fiction writer who has ever attempted to portray the night sky without betraying their lack of fundamental understanding. Hardy’s efforts are much better than most, as you might expect from a literary giant. So few writers appreciate that the stars, if described in detail, must be fixed in time, both nightly and annual, as well as in direction. There is nothing casual or random in the appearance of the night sky at all. Fortunately the errors are rarely obvious enough to spoil a good story!

If the sky is clear we will get a very good view of Mars in the east in the early evening. Sitting between the constellations of Leo (easy to find) and Cancer (hard to find), it will be rising about thirty degrees north of east at dusk and pass through due east at 8.30pm. By then Orion, below the high moon, will have moved to occupy a large part of the southern sky. If you follow Orion’s belt down to nearer the horizon then low in the southeast you will see the brightest star of them all, Sirius.

If you do happen to be awake late, then Mars will have moved to be due south and high in the sky by 1am. By this time the moon will have begun its steep descent in the west. If you are enjoying this in fresh air then you will either be very cold, or the owner of some excellent outdoor kit.

I woke up in the middle of the night and couldn’t go back to sleep. Some compensation was to be found outside, with a beautiful view of Orion, Sirius and Venus. All three have historically had some significance. Both Orion and Sirius have been used as seasonal markers, the ‘heliacal rising’ of Sirius being used as a forecast for flooding of the Nile in ancient Egypt. Orion is still known as a winter constellation in the northern hemisphere. The references to Venus are legion and include its use by the Maya to time the start of wars (see Anthony Aveni’s excellent book, ‘People and the Sky‘, for more on that.)

The picture is of Venus rising in the east-northeast just before five this morning, it took many attempts to get this photo as a cold wind kept rattling the tripod and its owner.

One of the many aspects of natural navigation that keeps me enthralled is that it never disappoints seasonally. As the warmth, light and ease of summer recedes, the stargazing options multiply.

Sirius is very visible on clear nights at this time to the south. Unfortunately last night it was obscured by a tree branch. Nature is obliging enough to make the stars rise 4 minutes earlier each evening and so this evening, in the absence of the moon our son did at least get a good view of the brightest star in the sky.

‘In Orion these [stars] are Rigel, Betelgeuse and Bellatrix; in Canis Major there is Sirius – and even Canis Minor, which essentially consists of only two stars, has the very bright Procyon. These are familiar names, but not perhaps for astronomical reasons. Bellatrix and Sirius are probably better known now as characters in J.K. Rowling’s Harry Potter books, while Betelgeuse was the title of a Tim Burton film, albeit with a different spelling [Beetlejuice].